Pump



Aug. 7, 1962 c. J. ERD 3,048,118

PUMP

Filed Feb. l0, 1961 2 Sheets-Sheet l FIGZ.

Aug- 7, 1962 c. J. ERD 3,048,118

PUMP

Filed Feb. l0, 1961 2 Sheets-Sheet 2 7l 55 /9 69 8' TI Fl@ 3 9 93 75 ,03v9 Y J J u ffl/2 94 7\ A7 73; lll 109 m 9 L e5 fof w o o fc5 99 j H9 J4l 37 27 3l i? 745 29 5 45\ 42 44 43 33 5i @mA/ZM 9* SW/LJ J M4 OD 4 F49United States Patent C) Mig PUMP Charies J. Erd, St. Louis, Mo.,assigner to Chas. S. Lewis & Company, Incorporated, St. Louis, Mo., acorporation of Missouri Filed Feb. l0, 1961, Ser.. No. 83,477 13 Claims.(Cl. 10S-87) This invention relates to pumps, and with regard to certainmore specific features, to pumps of the immersed type.

Among the several objects of the invention may be noted the provisionyof a centrifugal pump adapted successfully to pump corrosive, abrasiveand like deleterious or dangerous liquids, including slurries; theprovision of a pump of the class described which is constructed toprevent entry into its seals and bearings of such liquids and theirvapors and gases; the provision of a pump ott this class in which itssealing means are not only effectively protected `from contact with thedeleterious liquid being pumped, but are efiiciently lubricated; and theprovision of a pump of .this class adapted to operate for long periodsWithout the need for close attention or disassembly for majorreplacements. Other objects and features will be in part apparent and inpart pointed out hereinafter.

The invention accordingly comprises the elements and combinations ofelements, features of construction, and arrangements of parts which willbe exempliiied in the .structures hereinafter described, and the scopeof which will be indicated in the following claims.

In the accompanying drawings, in which one of various possibleembodiments of the invention is illustrated,

FIG. 1 is a side elevation illustrating a complete pump assembly madeaccording to the invention;

FIG. 2 is a horizontal cross section taken on line 2--2 of FIG. l;

FIG. 3 is an enlarged vertical and axial section of the pump assembly,the driving motor of the vassembly being omitted and mid portions of anupper barrel being cut away;

FIG. 4 is an enlarged detail cross section of an upper running seal; and

FIG. 5 is an enlarged detail cross section of a lower running seal.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

In the chemical industry are many corrosive, abrasive and dangerousliquids required to be pumped, such as, for example, sulfuric acid.These are usually damaging to the pumping apparatus and particularly 4tothe running seals required. The difficulties are increased when suchliquids are mixed with materials that form abrasive slurries. Forexample, in the production of chemical fertiliz ers, sulfuric acid ismixed with powdered phosphate rock, in order to produce a slurry fromwhich accrues phosphoric acid. The slurry is not only corrosive but alsohighly abrasive and very damaging to running seals and the like. Inorder to describe the invention, apparatus is illustrated which willsuccessfully pump such -a slurry which results `from mixing sulfuricacid, phosphoric acid and powdered phosphate rock and in connection withwhich several corrosive gases are liberated.

Referring now more particularly to the drawings, FIGS.

Eidl hatented Aug. 7, 1962 perforate barrel il. The barrel l1 issupported on the plate 7 by means of a bolted flange 13 surrounding theopening 9, and is ribbed for strength as shown at 15. On the flange i3is a bolted flange i7 of a motor-supporting pylon shown at i9. The pylonhas an upper flange 2l to which is bolted a vertically disposed drivingmotor 23.

Bolted to the lower end of the upper barrel 11 is an imperforate lowerbarrel v25. The lower end of barrel 25 has a flaring extension 27terminated by a lower flange 29. In the lextension 27 are one or moreoutlets, one of which is shown for example at 31 (FIG. 3). Above theextension 27 is an inward fiange 33 in which is bolted a downwardlyconverging nozzle-forming ring 35. The resulting inside convergingnozzle is lettered 37. The outside 39 of ring 35 forms an upwardlyflaring abrasiveresistant deflecting surface, part of which forms aton-gue 4l extending out through the opening 3l. In the case that`several openings Si are used, a tongue such as 41 extends from each.

Attached to the flange 29 is one wall 42 of a centrifugal pump casing43. The pump as a whole is lettered 45. The casing d3 has the usualvolute or scroll fonn generally used in centrifugal pumps. Bolted to thebottom of the casing is a removable pump wall 47 forming also a aredinlet 49. The impeller of the centrifugal pump 45 is shown at Si. ltsblades are indicated at 53.

T he impeller 51 is keyed to a shaft 55, being additionally held by anut 57 of streamlined exterior form and located in the inlet 4%.Attached with a force fit -to the hub of the impeller Si is a removableimpeller ring 52. Attached with a force ht to the casing 43 is aremovable casing ring 44. Rings d4 and 52 are composed of corrosionandwear-resistant materials, but they are not intended to maintain aleakless fit at their cylindrical interface. Consequently they may wearto a condition of wide clearance without requiring frequent renewal. Thecylindrical interface between the rings i4 and 52 is concentric with,but of a diameter greater than, the smallest outside diameter of ythenozzle-forming ring 35, so that eiliux of any leakage from between rings44 and 52 will occur as indicated by the darts a, adapted for radialdeilection along the outside curved surface 39 of ring 35. Since it iscontemplated that an abrasive slurry is to be handled, the material ofthe ring 35 is preferably made abrasive-resistant, as well ascorrosion-resistant.

The outlet of the scroll 43 is connected (FIG. 1) through an elbow 59with a riser pipe 6l, the upper end of which passes through anappropriate opening in the plate 7, by being held in position by a clampand sealing means 63. As shown at 65, the upper end of the riser pipe elis flanged for attachment to apparatus which is to receive .the pompage.

The shaft 55 extends upward ltlirough both barrels 25 and 11. Its upperend is attached to .the motor shaft by means of a coupling 67. The topof the upper barrel 11 is enclosed by a head 69. Attached to the upperend of the shaft and passing through the head is a sleeve 71, betweenwhich and the barrel 11 is located an antifriction bearing '73, adaptedto resist both radial and axial thrust. The sleeve '7l above bearing 73is formed with a shoulder 7S. This supports a wear ring '77 (FIG. 4),frictionally held by a rubber ring '79 to rotate with shaft 55. The ring'77 `forms part of a cartridge seal, indicated generally by the number`til.. This includes (FIG. 4) a jacket 83 within which is a secondstationary wear ring 85, sealed to the jacket by la resilient boot 87. Aspring-pressed ring S9 holds the boot 87 against the stationary ring 85.The pressure springs are indicated at 91.

A-t numeral 93 is shown an inlet for air or other gas lmder pressure.Hereinafter air will be referred to as one of the appropriate gases.This communicates with a spaans purge pipe 95, extending from the top ofthe barrel 11 and down through its lower end and into the barrel 25.Attached to the gas inlet 93 is an air pressure inlet pipe 94, leadingfrom suitable air compressing means. Connected with this pipe 94 is aninlet check valve 96 which permits flow from the compressing means tothe purge pipe 95, assuming that a suitable pressure is maintained bythe compressing means for `the purpose. Valve 96 will close and preventreverse ow if the pressure supplied by the compressing means falls belowthe pressure in pipe 95. At numeral 191 is shown an oil pipe, whichextends from an upper passage 193 down to lower oil feed passages 105and 125. Oil return passages are shown at 107. The upper passage 103communicates with the top of the bearing 733 and the underside of thecartridge seal 31. A sight gl-ass assembly 111 closes oil port 1119allowing for visual -inspection of the oil flow by means of a glass`disc 112.

Bolted to the underside of the lower flange 99 of barrel 11, and locatedWithin the barrel 25, is a cap 113. This also holds a stationarydiaphragm ring 115 in place against the bottom of llange 99. Attached tothe mid portion of the shaft 55 isa sleeve 117, -between which and theflange portion 99 of barrel 11 is located an antifriction, radialthrustbearing 119. The lower portion of the sleeve 117 is constructed as acentrifugal oil impeller having a running t in the diaphragm 115 andhaving formed therein angled passages 121. The inlets of these passagesabove diaphragm 115 are axially directed and the lower outlets belowdiaphragm 115 are radially directed, so that upon rotation they willdraw down oil from a supply 123 in barrel 11, and produce oil pressurein the cap 113. Oil is thus forced through angled passages 125 andpassage 105 to the oil pipe 191 in which the head pressure establishesin cap 113 a pressure which is in excess of the head pressure of -oilwhich is carried to the level shown in `barrel 11. Moreover, acirculation is established from the inside of the barrel 11, rotatingpassages 121, passages 125, 105, pipe 191 and passage 1013 to the top ofbearing 73 and back to the barrel 11. Thus bearing 73 is lubricated by acascade of oil down through it for return to the oil supply 123 inbarrel 11. Bearing 119 is lubricated by immersion in this oil supply123. Hereinafter, the lower end of the sleeve 117, including itspassages 121, may be referred to in general as a centrifugal oil pump,`and as such it is numbered 127.

The oil pressure established by the centrifugal oil pump 127 actingagainst the hydraulic head in pipe 1411 is used to force oil through arunning seal between shaft 55 and the cap 113. The seal is constitutedby a yceramic ring 129, located in a recess at the bottom of the cap 113and held stationary by a resilient O-ring 131 (FIG. 5). At numeral 133is shown a carbon sealing ring which is held to the shaft 55 by anO-ring 135. Above the carbon ring 133 is a washer 137 upon which pressesa spring 139. Spring 139 is located in an inverted cup 141, attached byfasteners 143 .to the lower end of the oil pump 127. The cup 141surrounds the spring 139 and also contains the upper end of the carbonring 133. The running seal provided between the ceramic ring 129 and thecarbon ring 133 is disposed in a radial plane, and is thereforesubstantially unaffected as to leakage by any whip that may occur in theshaft 55.

Lubrication for the seal is provided by the pressure in the cap 113,this pressure being greater than that which could be supplied by thelevel 123 of oil carried in barrel 11, as above explained. Thus it willbe seen that a pressure dilerential is established across the slidinginterface between rings 129 and 133 from the oil-filled inside of cap113 to the inside of barrel 25. This will transport a small amount ofoil across the interface-for lubrication. The pressure differential inthe direction described prevents any gas or vapor from moving from theinside of barrel 25 into the seal 129, 133.

Operation is as follows:

First, it is assumed that the upper barrel 11 has been suitably filledwith oil to level 123, and that air under pressure is supplied to theinlet 93 at sufcient pressure to prevent establishment of a liquid levelin the barrel 25. in other words, the air pressure in barrel 25 issuicient that the barrel acts as an air trap. Preferably, sufficient airis supplied so that it will bubble outward through the nozzle 37, asindicated at the darts 145. This air ultimately escapes by bubbling upthrough the slurry 3 to escape at level 5.

Upon exciting the motor 23, shaft 55 is rotated, thus operating thecentrifugal oil pump 127 and the main centrifugal pump 45. The latterdraws in the slurry of acid and abrasive through the inlet 49, expellingit through the casing 43 .and riser pipe 61. Pressure established forthis purpose in the casing of pump 45 will produce some leakage throughthe cylindrical interface between the rings 4d and 52. This leakage isdeflected by the outside deflector surface of the nozzle ring 35 andinto the main body of the slurry. Air under pressure within-the barrel,escaping at the nozzle 37, prevents any of this material from enteringthe barrel 25. Thus the head pressure of the slurry 3 in the sump 1 isprevented from establishing any level of slurry in the barrel 25, whichmight reach the seal 129, 133. Moreover, by preventing the establishmentof a level of slurry at any level in the barrel 25 and maintaining adownward How of air, there is minimized the chance of access to the seal129, 133 of any corrosive gases or vapors. These are substantiallyblocked from entry through the nozzle 37 into barrel 25.

The centrifugal oil pump 127, in addition to furnishing circulating oilfor the upper bearing 73, furnishes a pressure differential across theseal 129, 133 which prevents air from escaping from the barrel 25 at theseal. It also prevents any contaminating gases or vapors (which mightenter the nozzle 37 under unusual conditions) from reaching the runninginterface of the seal 129, 133. For example such small amounts mightenter under conditions of low liquid level in sump 3 with violentagitation within the member 27. it is to be understood, however, thatunder conditions of loss of air pressure in the barrel 25, some lowliquid level might be carried in the barrel 25 (below level 5 in thesump 1), the `barrel 25 then acting purely as a diving bell. Under suchconditions, some but not all of the advantages of the invention wouldaccrue, the chief one being the prevention of the rise in barrel 25 of aliquid level to the seal 129, 133, because outward air movement up pipeis checked by the action of check valve 9e.

Under any operating conditions, the small amount of oil that may escapethrough seal 129, 133 from the upper 'barrel 11 into the lower barrel 25and pass out of the nozzle 37 is so small as to be inconsequential .as acontaminant in the slurry.

In view of the above, it will be seen that the several objects of theinvention are achieved and otheradvantageous results attained.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim:

1. A pump assembly for use in a liquid sump comprising an imperforatebarrel adapted for upright location in the liquid, a shaft extendingthrough said barrel, rotary sealing means between the shaft and an upperportion connected to said barrel, driving means for said shaft abovesaid sealing means, a centrifugal pump having an impeller attached tosaid shaft below said barrel and also having a casing around theimpeller, connecting means between said barrel and said casing, saidconnecting means having at least one opening exposed to movespaans menttherethrough of fluid in said sump, said barrel having lower end outletmeans in communication with the sump through said opening, a secondbarrel extending upward from said first-named barrel and having an upperbearing for said shaft and a lower bearing therefor, said upper barrelbeing adapted to form an oil sump, means located at the upper end of thefirst-named barrel and forming a pressure chamber around said rotaryseal for the shaft, 'and shaft-driven oil pump means having an inletconnection with the upper barrel .and an outlet in said pressure chamberand adapted to produce a pressure differential across the seal from saidpressure chamber tcsaid first-named barrel.

2. A pump assembly according to claim l, including an oil-head-pressureconnection between said pressure chamber and the upper end of the upperbarrel at a location above said upper bearing.

3. A pump assembly according to claim 2, wherein said oil pump means isof the centrifugal type having an impeller on said shaft where it passesthrough said pressure chamber.

4. A pump assembly for use in a liquid sump comprising an imperforatelower barrel adapted for upright location in the liquid and having anoutlet at its lower end submerged below the liquid surface level, anupperend assembly above said barrel forming a chamber adapted to carrypressure in excess of the pressure in the barrel, an upper container onthe lower barrel forming an oil sump, a shaft extending through saidupper container, the lower barrel and said chamber, a seal between saidassembly and the shaft separating said chamber from the space in thebarrel, means above the upper container adapted lto rotate the shaft,bearing means in said upper container for said shaft and adapted to belubricated by said oil, the lower end of said shaft extending downwardfrom said lower outlet of the lower barrel, centrifugal oil pump meansin said pressure chamber and driven by said shaft, said centrifugal oilpump means having oil inlet connecting means with the interior of theupper container below the surface level of the' oil therein and adaptedto generate oil pressure at said seal and for circulation through saidbearing means, a centrifugal pump having an impeller attached to saidshaft below the lower barrel and also having a casing around theimpeller, connecting means between the outlet of the lower barrel andsaid casing, said connecting means having `at least one opening exposed-to movement therethrough of -uid in said sump, said outlet being incommunication with the sump through said opening.

5. A pump assembly for use in a liquid sump comprising an imperforatebarrel adapted for upright location in lthe liquid, a shaft extendingthrough said barrel, rotary sealing means between the shaft and an upperportion connected to said barrel, driving means for said shaft abovesaid sealing means, a centrifugal pump having an impeller attached tosaid shaft below said barrel and also having a casing around theimpeller, connecting means between said barrel and said casing, saidconnecting means having at least yone opening exposed to movementtherethrough of iiuid in said sump, said barrel having lower end outletmeans in communication with the sump through said opening, said impellerand said casing having an unsealed circular running clearancetherebetween subject to an annular liquid iow of liquid therethroughfrom the inside of the casing to the sump, said lower end outlet meansof the barrel being in the'shape of `a converging nozzle connected withthe lower end of the barrel and having a circular end closelysurrounding the shaft to form a comparatively narrow annular gas outlet,the

outside of said nozzle being shaped to form an outside convergingdeilecting surface in the path of said annular leakage flow to guide itradially away from said lower outlet of the barrel, and means adapted tointroduce a gas under pressure into said barrel for annular flow from dsaid converging nozzle within the confinesv of said annular leakage ow.

6. A pump assembly for use in a liquid sump comprising an imperforatebarrel adapted for upright location in the liquid, a shaft, bearingmeans at the upper end of the barrel for said shaft, said barrel havinga lower outlet formed as a converging nozzle, said shaft extendingthrough the barrel and out of said converging nozzle with an `annularspace between them, means adapted to move air under pressure through thebarrel and through said annular space, a centrifugal pump having acasing attached at the lower end of the barrel and an impeller `attachedto said shaft, said impeller and said casing having beyond said nozzlean unsealed circular running clearance therebetween of an effectivediameter greater than the outside diameter of said annular space,whereby eiux of leakage from the circular clearance is directed awayfrom said annular space.

7. A pump assembly according to claim 6, wherein the outside of saidconverging nozzle is curved outwardly to a diameter .greater than `theoutside `diameter of said unsealed running clearance for the deflectionof leakage flow therefrom away from the annular outlet.

8. A pump assembiy for use in a liquid sump comprising an imperforatelower barrel adapted for upright location in the liquid and having anoutiet at its lower end submerged below .the liquid surface level, saidlower barrel having an upper-end assembly forming a chamber adapted tocarry pressure in excess of the pressure in the barrel, an upper barrelextending from the lower barrel and forming `an oil sump at its bottom,a shaft extending through both barrels and said chamber, means above theupper barrel adapted to rotate the shaft, bearing means at the top andbottom of the upper barrel for said shaft, the bearing at the bottombeing submerged in said oil, the lower end of said shaft extendingdownward from said lower outlet of the lower barrel, a centrifugal pumphaving an impeller attached to said shaft below the lower barrel andalso having a casing around the impeller, connecting means between theoutlet of the lower barrel and said casing, said connecting means havingat least one opening exposed to movement therethrough of fluid in saidsump, said outlet being in communication with the sump through saidopening, centrifugal oil pump means in said pressure chamber and drivenby said shaft, said centrifugal oil pump means having oil inletconnecting means with the interior `of the upper barrel below thesurface level of the oil therein.

9. A pump assembly according to claim 8, including an oil-head-pressureconnection between said pressure chamber and a location in the upperbarrel above said upper bearing.

10. A pump assembly according to claim 9, including a gas pressureconnection with said lower barrel.

ll. A pump assembly according to claim l0 wherein the oil-head-pressurein said oil-head-pressure connection is greater than the gas pressure insaid lower barrel.

l2. A pump assembly according to claim l1, wherein said outlet of thelower barrel is formed as a converging nozzle inwardly to constrict gasow annularly around the shaft.

13. A pump assembly according to claim l2, including an unsealedcircular running clearance between the impeller and the casing subjectto an annular leakage ow of liquid therefrom, the diameter of saidclearance being larger than the outlet end of said nozzle, the outsidesurface of said nozzle adapted to form a deiector for said leakage ilowaway from the gas outlet end of said nozzle.

References Cited in the le of this patent UNITED STATES PATENTS

